L4 : Types of SQL Commands | Complete SQL Course 2024 | Jobs | Placements

Summary

This video script delves into the world of SQL commands, categorizing them based on their functionalities. It covers Data Query Language commands for retrieving data, Data Manipulation Language for inserting, updating, and deleting data, Data Definition Language for defining database structure and schema, Data Control Language for managing access and security, and Transaction Control Language for managing database transactions. The script provides examples, such as selecting student details and updating student records, to illustrate the practical application of these SQL command categories.

Takeaways

• 😀 SQL commands are divided into different categories based on their functionalities.
• 😀 Data Query Language (DQL) commands help in querying data from the database.
• 😀 Data Manipulation Language (DML) commands are used to manipulate data stored in the database.
• 😀 Data Definition Language (DDL) commands define the structure and schema of the database.
• 😀 Data Control Language (DCL) commands manage access control and security of the data.
• 😀 Transaction Control Language (TCL) commands handle transactions within the database.
• 😀 The SELECT command is used to retrieve data from the database.
• 😀 The INSERT, DELETE, and UPDATE commands are part of DML, used for data manipulation.
• 😀 The CREATE, ALTER, DROP, TRUNCATE, and RENAME commands are part of DDL for defining and modifying the database structure.
• 😀 GRANT and REVOKE commands in DCL manage permissions for accessing data.
• 😀 COMMIT, ROLLBACK, and SAVEPOINT commands in TCL handle the management of database transactions.

Q & A

What is the main topic of the video script?

The main topic of the video script is about various types of SQL commands categorized based on their functionalities.

What are the different categories of SQL commands mentioned in the script?

The script mentions categories such as Data Query Language commands, Data Manipulation Language commands, Data Definition Language commands, Data Control Language commands, and Transaction Control Language commands.

What is the purpose of Data Query Language (DQL) commands?

Data Query Language (DQL) commands are used to retrieve data from the database, such as the SELECT command.

Can you provide an example of how DQL commands are used in the script?

An example given in the script is using the SELECT command to fetch details about a student in class 2 with a roll number 3.

What does Data Manipulation Language (DML) involve?

Data Manipulation Language (DML) involves commands that help in data manipulation like INSERT, DELETE, and UPDATE in the database.

How are Data Definition Language (DDL) commands described in the script?

DDL commands, such as CREATE, ALTER, and DROP, are used to define the structure and schema of the database.

What is the role of Data Control Language (DCL) commands?

Data Control Language (DCL) commands are used to control access to the data, such as granting and revoking permissions.

What does the script say about Transaction Control Language (TCL) commands?

TCL commands, like COMMIT, ROLLBACK, and SAVEPOINT, are used to manage transactions within a database.

What is the significance of the COMMIT command in TCL?

The COMMIT command is used to save the changes made during a transaction to the database, making them permanent.

How does the script explain the use of the SELECT command in DQL?

The script explains that the SELECT command in DQL is used to fetch data from the database, such as retrieving details of a student based on specific criteria.

What is an example of a data manipulation scenario described in the script using DML commands?

An example given is the promotion of a student from one semester to another, where the UPDATE command would be used to reflect this change in the database.